195 20 Sustainable management of the Lake Eyre Basin rivers – regulate, educate or open the gate? Tom Crothers Introduction The Lake Eyre Basin covers about one-seventh of Australia, more than 1 million km2 across Queensland, New South Wales, South Australia and the Northern Territory (see Chapter 1). It is of international and national environmental significance and includes areas of high economic, social and cultural heritage values. The significance of the Basin as an international and national asset is reflected in the Lake Eyre Basin Intergovernmental Agreement, established in 2001, to protect the rivers and related natural resources and signed by the Australian, Queensland, South Australia and the Northern Territory governments (see Chapter 7). The Lake Eyre Basin is one of the world’s largest internally draining river basins, with many ecosystems, people and processes dependent on the rivers (Kingsford et al. 2014). Most of the water that flows into Lake Eyre originates in the upstream Georgina and Diamantina Rivers and Cooper Creek, two iconic dryland river systems with near natural and highly variable flow regimes (Puckridge 1999 Kingsford et al. 2014). Cooper Creek flows beyond the Queensland border into South Australia, and covers an area of 296 000 km2, ~26% of the Lake Eyre Basin. It includes the Thomson, Barcoo and Cooper subcatchments in Queensland (Fig. 20.1). The major tributaries of Cooper Creek are the Barcoo, Thomson, Darr, Alice and Wilson Rivers, and Landsborough, Towerhill, Torrens and Kyabra Creeks. Cooper Creek forms a network of channels, waterholes, lakes and extensive floodplains, predominantly in the lower part of the catchment, known as the Channel Country. These wetlands and waterholes connect during floods, and progressively disconnect as the system dries, the predominant condition. Some waterholes are permanent, providing important refuges for waterbirds, fish, other animals and plants (Silcock 2009 Silcock 2010 Kerezsy et al. 2014 Kingsford et al. 2014). Cooper Creek has an extensive floodplain, south of Windorah, divided into two major sections, one in Queensland and the other in South Australia, separated by the ‘Innamincka choke’, a narrow channel and floodplain constricted by stony hills near the border. Above this, the Queensland floodplain can be up to 80 km wide, with flows connecting large swamps and the large temporary Lake Yamma Yamma. The South Australian section has numerous, widely distributed, shallow, ephemeral freshwater and saline lakes, intersected by parallel dunes. The Georgina and Diamantina River catchments form the other iconic western river system flowing from Queensland to Kati Thanda-Lake Eyre (Fig. 20.2). Their catchments cover ~365 000 km2, ~32% of the Lake Eyre Basin. The Georgina River starts on the Barkly